Mobile users are typically registered with a home wireless communication system. The home wireless communication system includes a database that contains all the subscribers within the home service area of the home wireless communication system. This database is commonly referred to as a Home Location Register (HLR).
HLRs are capable of conversing in a particular protocol. In typical wireless communication systems, an HLR is only capable of conversing in a single protocol.
Cellular service providers allow mobile users to cross between systems using different protocols. However, HLRs will typically converse in one protocol and ignore messages in any other protocol. This can lead to problems when a mobile user roams from their home coverage area to a coverage area that utilizes a different protocol than their home wireless communication system. This can make determining the location of a mobile station or the delivery of calls to a mobile station difficult or impossible.
Wireless service providers have occasion to move subscriber records from a first HLR to a second HLR that converses in a different protocol than the first protocol. When a call request is received for the mobile station, the wireless communication system requests location information relating to the called mobile station from the first HLR. If the subscriber record is not found in the first HLR because it has been moved, the HLR sends a return error message. The return error message will typically include an unassigned directory number for the called mobile station.
The wireless communication system then sends a location request for the called mobile station to the second HLR. If the second HLR includes a subscriber record for the called mobile station, the wireless communication system utilizes the information from the second HLR.
One problem with this scenario is that the information obtained is not remembered by the wireless communication system. Every time a call for a mobile station is received the same, processor-intensive processing occurs.
Therefore, a need exists for a method that allows a service provider to move subscriber records from one HLR to another that utilizes a different protocol without wasting system resources each time a call is received for the moved mobile station. Further, a need exists for a method that allows a wireless communication system to return location information relating to a mobile station whose subscriber record has been moved in a shorter amount of time.